If you are a textile engineering student or a textile professional, then you must have in depth knowledge about knitting as it is an essential part of textile. So, in this post, I will discuss about warp knitting, weft knitting and jacquard knitting.
Warp knitting is made on flat bed machines and the parallel lines of yarns are arranged like a woven fabric. Each yarn is controlled by a separate needle which loops it onto itself. The yarns are connected to the next vertical row by moving back and forth from side by side directed by metal guides.
The following are the major constructions produced by the warp knitting method:
Generally “tricot” refers to all warp knitting fabrics. Specifically it applies to fabric with plain jersey stitch produced on the tricot machine and is characterized by fine vertical wales on the face and crosswise under laps on the back. The fabric may be called tricot jersey and may be distinguished as one, two, or three-bar tricot according to the kinds of guide bars that control the fabric in the making.
- high elasticity in the crosswise direction,
- good dimensional stability,
- high water and air permeability,
- high tear strength,
- no tendency to ravel,
- soft in handle,
- food wrinkle resistance.
End Uses: Lingerie, blouse, shirts, dresses, outwear.
The raschel machine has the ability to stitch and lay-in yarns through the use of multiple guide bars. By using selected machines and special attachments, it can produce lacy, open-work fabrics of great variety and can make them either stable or elastic, as required.
- good abrasion resistance,
- no tendency to ravel,
- good dimension stability,
- good shrink resistance.
End Uses: Sheer laces, nets, draperies carpets, jackets, trousers, pantyhose.
This machine produces a fabric made with two set of yarns knitted opposite to each other in a diagonal formation. The face of the fabric has a very fine rib with a diagonal structure on the back. The fabric is run-proof intended mainly for gloves and lingerie.
The largest proportions of knitted fabrics used today are weft knits. Weft knitting is made on either flat or circular machines. Four basic types of stitches used in weft knitting are described below:
Plain or Jersey Stitch:
This is made on both flat and circular machines. Since the loops are formed in one direction only, the two sides of the fabric have a different appearance. One popular variation is single jersey.
A rib fabric is characterized by lengthwise ribs formed by wales alternating from face to back. It is known as 1 x 1 rib. If every two wales alternate it is called a 2 x 2 rib. One of the variations of this construction for outerwear is called double jersey. The 1 x 1 rib is the simplest rib fabric in which the structure includes alternate wale of plain ad reversed plain stitches.
The machine produces fancy knit fabrics with interloping stitches in which they reverse and the face of a plain knit in alternate courses. The fabric is same on the both sides.
The two jersey constructions are interlocked, both sides look like single jersey.
Both weft knitting and warp knitting can incorporate the Jacquard mechanism to produce multicolored designs. The punched card technique used in weaving is also adapted to knitting. Another technique is electronic or electro-magnetic devices to control individual needles. A third means is the use of a strip of film encoded in a boxed fashion. The film is divided into successive opaque and transparent squares that act similarly to the holes as the jacquard card or paper tape. A lens directs light through the moving film to photo transistor to select the particular needle for each stitch. Jacquard knits are made on flat bed or circular knitting machines.
That’s all for today. Hope this post will help you learn something more about warp knitting, weft knitting and jacquard knitting.